Quick Opening Closures (QOC)
Quick opening closures are the critical safety component of pig traps. Mechasol provides multiple closure designs, selected based on pressure class, opening frequency, required safety level, and operator ergonomics.
Features and Design Fabrication: Designed to ASME B31.4, ASME B31.8, and ASME Section VIII Div. 1 Codes Mechasol’s QOCs come with the internal locking mechanism. Mechasol’s QOCs can be positioned in a horizontal, vertical or inclined alingnments Mechasol provides manual and spare parts for this operation. Mechasol’s QOCs can also be designed with a mechanic or hydraulic (automatic) opening systems if required. All Closures are available with the sandblasted and primer coated and color of customer’s choice Quick Closures can be hydrostatically tested on request Internal inspection and test certificates will be provided for each item Third party inspection can be provided
| Where to use? Scrapper and Pig Launchers/Receivers Filter vessels, Seperators Pressure Vessels Acess opening on Scrubbers, Filters, Strainers Storage Tanks Shell and Tube Heat Exchangers Autoclave Doors Manways in Pressure Vessels Terminal Manifolds Meter Provers Metering Skid Systems Chemical Reactors
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Types
A) Hinged Clamp Ring Closure (Segmented / Split Ring)
Fast operation with clamp segments
Very common for frequent pigging
Good for mid-high pressure depending on design
B) Breech Lock Closure (Bayonet / Lug Type)
High integrity mechanical locking using lugs
Suitable for higher pressures and frequent cycling
Robust and reliable for harsh conditions
C) Yoke / Fork Type Closure
Mechanical yoke applies closure force
Good for moderate pressure and quick access
Often chosen where simplicity is required
D) Threaded Plug Closure (Limited use)
E) Bolted Blind / Studded Cover (Not “quick”, but relevant alternative)
F ) Quick Opening Closure with sector locking system ( SECTOR TYPE )
Composed from 2 forged pieces: Hub and cover.The opening / closing is performed by acting on a rapid mechanism which locks / unlocks the sectors.
Mechasol can provide manual, assisted, or hydraulic/pneumatic actuator-aided closure mechanisms depending on size and required ergonomics.
Safety Interlock Systems (Non-Negotiable)
Every quick opening closure must prevent:
Typical interlocks
Pressure warning device (PWD) / bleed lock
Mechanical key interlock system
Positive locking indicators (visual + mechanical)
Sequenced venting requirements (cannot unlock until vented)
Selection Parameters for Quick Opening Closures
Pressure class and nozzle neck design
Opening frequency (daily/weekly/monthly)
Closure size (operator handling)
Corrosion/sour service (materials, seals)
Ambient environment (marine / desert / arctic)
Required safety philosophy (key interlock vs smart sensors)
Maintenance strategy (seal replacement intervals, spares)
